ZIP using LZ77 is mainly used as a compression algorithm. In ZIP, longest coincidence searching is performed with respect to a character string of a compression target by using a slide window, and a compression code is generated. That is, in ZIP, in a case where there is a character string, which has been already subjected to compression encoding, and is identical to the character string of the compression target, in data stored in the slide window, compression is performed by representing the compression code with a relative address and a length from the slide window. The longest coincidence searching using the slide window is performed in byte unit.
Japanese Laid-open Patent Publication No. 10-283368
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